Flywheel energy storage device

Abstract

The utility model discloses a flywheel energy storage device. The flywheel energy storage device comprises a motor housing; the motor stator is arranged in the motor shell and is fixedly connected with the motor shell; a motor rotor; a closed loop is formed in the heat exchange pipe, a cooling working medium circulates in the heat exchange pipe, the heat exchange pipe comprises a first heat exchange pipe and a second heat exchange pipe which are communicated with each other, the first heat exchange pipe is located outside the motor shell, and the second heat exchange pipe penetrates through the motor shell and is located inside the motor stator; and at least part of the second heat exchange tube is arranged adjacent to the motor rotor in the radial direction of the motor stator. Therefore, through the arrangement of the heat exchange tube, continuous heat dissipation of the motor stator is realized, the temperature of one side, adjacent to the motor rotor, of the motor stator in the radial direction is effectively reduced, the heat radiation intensity between the motor rotor and the motor stator is enhanced, the temperature of the motor rotor is reduced, and thus the working performance of the flywheel energy storage equipment is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of flywheel energy storage, in particular to a flywheel energy storage device. Background Art

[0002] A flywheel energy storage device is a type of energy storage method that converts electrical energy into kinetic energy for storage and releases the kinetic energy as electrical energy when necessary. Its energy storage and energy release mainly rely on an electric motor. Therefore, as a key link in flywheel energy storage, the working state of the electric motor affects the working ability of the flywheel energy storage device.

[0003] The rotational speed of the flywheel energy storage device can reach 40,000 r / min to 50,000 r / min. To reduce the wind resistance of the flywheel energy storage device at high rotational speeds, the rotor usually operates under low pressure or in a vacuum. At the same time, to reduce the frictional loss of the device bearings, electromagnetic bearings are often used to suspend the flywheel rotor in a vacuum, and the efficiency of the flywheel energy storage device can reach more than 95%. However, in a vacuum environment, the heat generated by the rotor can only be transferred outward by thermal radiation, and the radiation intensity is very weak, making it difficult to dissipate the heat generated by the device rotor, resulting in a continuous increase in the rotor temperature and even causing demagnetization of the magnetic steel and damage to the electric motor.

[0004] In related technologies, the rotor cooling technology of flywheel energy storage devices can be mainly divided into contact and non-contact heat dissipation methods. Contact heat dissipation mainly transfers the heat out by directly contacting the rotor with a coolant and dissipating it outside the flywheel device. This method has very high requirements for the sealing between the rotor and the vacuum housing. Non-contact heat dissipation mainly transfers the heat of the rotor to the low-temperature side in the form of radiation. The radiation heat transfer intensity is low, and means to enhance radiation heat transfer, such as increasing the heat transfer temperature difference, heat transfer area, and surface emissivity, are required. Summary of the Utility Model

[0005] The utility model aims to at least solve one of the technical problems existing in the prior art. For this purpose, an object of the utility model is to provide a flywheel energy storage device, which can effectively reduce the temperatures of the motor stator and the motor rotor and has better working performance.

[0006] The flywheel energy storage device according to an embodiment of the utility model includes: a motor housing; a motor stator disposed inside the motor housing and fixedly connected to the motor housing, the motor stator having an accommodation space; a motor rotor rotatably disposed in the accommodation space; a heat exchange tube in which a closed loop is formed and a cooling working medium flows, the heat exchange tube including a first heat exchange tube and a second heat exchange tube that are connected to each other, the first heat exchange tube being located outside the motor housing, the second heat exchange tube passing through the motor housing and being located inside the motor stator, and at least a part of the second heat exchange tube being disposed adjacent to the motor rotor in the radial direction of the motor stator.

[0007] Thus, through the arrangement of the heat exchange tubes, not only can continuous heat dissipation of the motor stator be achieved, effectively reducing the temperature of the motor stator on the side adjacent to the motor rotor in the radial direction, but also the heat radiation intensity between the motor rotor and the motor stator can be enhanced, reducing the temperature of the motor rotor, thereby improving the working performance of the flywheel energy storage device.

[0008] In some examples of the present utility model, the first heat exchange tube extends in the up and down direction, the second heat exchange tube is at least partially bent in the up and down direction, and both ends of the second heat exchange tube close to the outside are connected to the first heat exchange tube.

[0009] In some examples of the present utility model, the motor stator includes: a stator winding and a stator lamination. The stator winding is wound around the stator lamination. The stator lamination is fixedly connected to the motor housing and is provided with an avoidance channel, and at least part of the second heat exchange tube is disposed in the avoidance channel.

[0010] In some examples of the present utility model, the second heat exchange tube includes: a first heat exchange portion, a second heat exchange portion, and a third heat exchange portion connected in sequence. The first heat exchange portion and the third heat exchange portion extend in the radial direction and are spaced apart in the up and down direction. The second heat exchange portion extends in the up and down direction; the avoidance channel includes: a first avoidance portion, a second avoidance portion, and a third avoidance portion connected in sequence. The first avoidance portion and the third avoidance portion extend in the radial direction and are spaced apart in the up and down direction. The second avoidance portion extends in the up and down direction and is adjacent to the motor rotor in the radial direction; the first heat exchange portion is disposed in the first avoidance portion, the second heat exchange portion is disposed in the second avoidance portion, and the third heat exchange portion is disposed in the third avoidance portion.

[0011] In some examples of the present utility model, the motor housing is provided with a first avoidance hole and a second avoidance hole. The first avoidance hole avoids the first heat exchange portion, and the second avoidance hole avoids the third heat exchange portion.

[0012] In some examples of the present utility model, a first fin is provided on the circumferential outer side of the motor housing. The first fin extends in the up and down direction. There are a plurality of the first fins and they are spaced apart in the circumferential direction. An avoidance groove is formed between two adjacent first fins. The first avoidance hole and the second avoidance hole are respectively communicated with the avoidance groove.

[0013] In some examples of the present utility model, a liquefaction portion is provided at the upper end of the first heat exchange tube. A second fin is provided on the outer side of the liquefaction portion. The second heat exchange tube is connected below the liquefaction portion.

[0014] In some examples of the present utility model, there are multiple second fins, and the multiple second fins are spaced apart in the axial direction and / or circumferential direction of the liquefaction part.

[0015] In some examples of the present utility model, there are multiple heat exchange tubes, and the multiple heat exchange tubes are spaced apart in the circumferential direction of the motor stator.

[0016] In some examples of the present utility model, the flywheel energy storage device further includes: an upper end cover assembly, a lower end cover assembly, and a flywheel rotor. The upper end cover assembly is arranged at the upper end of the motor housing and fixedly connected to the motor housing. The lower end cover assembly is arranged at the lower end of the motor housing and fixedly connected to the motor housing. The flywheel rotor is arranged inside the motor housing and connected below the motor rotor. Magnetic suspension bearings are respectively arranged inside the upper end cover assembly and the lower end cover assembly to enable the flywheel rotor and the motor rotor to be selectively magnetically suspended in the up and down direction.

[0017] The additional aspects and advantages of the present utility model will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present utility model. Description of the Drawings

[0018] The above and / or additional aspects and advantages of the present utility model will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0019] Figure 1 is a schematic diagram of a flywheel energy storage device according to an embodiment of the present utility model;

[0020] Figure 2 is a schematic diagram of a flywheel energy storage device according to an embodiment of the present utility model;

[0021] Figure 3 is a cross-sectional view of the flywheel energy storage device according to an embodiment of the present utility model along the A-A direction;

[0022] Figure 4 is Figure 3 a schematic diagram of area A in

[0023] Figure 5 is an exploded view of a flywheel energy storage device according to an embodiment of the present utility model;

[0024] Figure 6 is a schematic diagram of a heat exchange tube according to an embodiment of the present utility model;

[0025] Figure 7 is a schematic diagram of a stator lamination according to an embodiment of the present utility model;

[0026] Figure 8It is a schematic diagram of a motor housing according to an embodiment of the present utility model.

[0027] Reference numerals:

[0028] 100, flywheel energy storage device;

[0029] 10, motor housing; 11, first avoidance hole; 12, second avoidance hole; 13, first fin; 14, avoidance groove;

[0030] 20, motor rotor;

[0031] 30, motor stator; 31, stator winding; 32, stator lamination; 321, avoidance channel; 3211, first avoidance portion; 3212, second avoidance portion; 3213, third avoidance portion;

[0032] 40, heat exchange tube; 41, first heat exchange tube; 411, liquefaction portion; 412, second fin; 42, second heat exchange tube; 421, first heat exchange portion; 422, second heat exchange portion; 423, third heat exchange portion;

[0033] 50, upper end cover assembly; 60, lower end cover assembly; 70, flywheel rotor. Detailed implementation manners

[0034] The embodiments of the present utility model will be described in detail below. The embodiments described with reference to the drawings are exemplary. The embodiments of the present utility model will be described in detail below.

[0035] Below, reference is made to Figures 1-8 Describe the flywheel energy storage device 100 according to an embodiment of the present utility model.

[0036] Combined with Figures 1-5 As shown, the flywheel energy storage device 100 according to the present utility model may mainly include: a motor housing 10, a motor stator 30, a motor rotor 20, and a heat exchange tube 40.

[0037] Among them, the motor stator 30 is disposed inside the motor housing 10 and fixedly connected to the motor housing 10. The motor stator 30 is provided with an accommodation space, and the motor rotor 20 is rotatably disposed in the accommodation space. At the same time, the flywheel energy storage device 100 may further include: an upper end cover assembly 50, a lower end cover assembly 60, and a flywheel rotor 70. The upper end cover assembly 50 is disposed at the upper end of the motor housing 10 and fixedly connected to the motor housing 10. The lower end cover assembly 60 is disposed at the lower end of the motor housing 10 and fixedly connected to the motor housing 10. The flywheel rotor 70 is disposed inside the motor housing 10 and connected below the motor rotor 20. Magnetic suspension bearings are respectively disposed inside the upper end cover assembly 50 and the lower end cover assembly 60 to magnetically suspend the flywheel rotor 70 and the motor rotor 20 selectively in the vertical direction.

[0038] In this way, the motor housing 10, the upper end cap assembly 50 and the lower end cap assembly 60 can jointly form a vacuum environment during the operation of the flywheel energy storage device 100. The flywheel rotor 70 is connected to the motor rotor 20 and they jointly form a rotor. When the flywheel energy storage device 100 operates, the magnetic suspension bearings in the upper end cap assembly 50 and the lower end cap assembly 60 are relied on to control the suspension of the rotor. Among them, there is a clearance fit between the rotor and the upper end cap assembly 50 and the lower end cap assembly 60, and the rotor can move slightly within the upper end cap assembly 50 and the lower end cap assembly 60 to ensure that the rotor has no contact with other parts under the working state.

[0039] The flywheel energy storage device 100 can convert electrical energy into kinetic energy for storage, or convert kinetic energy into electrical energy for release. Specifically, during charging, the motor stator 30 generates a magnetic field to drive the motor rotor 20 to rotate, and the motor rotor 20 drives the flywheel rotor 70 to rotate. At this time, the flywheel rotor 70 stores kinetic energy. During discharging, the flywheel rotor 70 uses the stored kinetic energy to drive the motor rotor 20 to rotate. At this time, the motor stator 30 generates electricity and releases the kinetic energy as electrical energy.

[0040] It can be understood that affected by the copper loss and iron loss of the motor, both the motor stator 30 and the motor rotor 20 will generate a large amount of heat energy.

[0041] Furthermore, a closed loop is formed within the heat exchange tube 40 and a cooling working medium flows through it. The heat exchange tube 40 can include a first heat exchange tube 41 and a second heat exchange tube 42 that are connected to each other. The first heat exchange tube 41 is located outside the motor housing 10, and the second heat exchange tube 42 penetrates the motor housing 10 and is located inside the motor stator 30. At least a part of the second heat exchange tube 42 is arranged adjacent to the motor rotor 20 in the radial direction of the motor stator 30.

[0042] In this way, the cooling working medium in the second heat exchange tube 42 can absorb the heat of the motor stator 30, especially the heat on the side of the motor stator 30 adjacent to the motor rotor 20 in the radial direction. The cooling working medium absorbs heat and vaporizes, then flows along the closed loop to the first heat exchange tube 41, and exchanges heat with the external air here. The gaseous cooling working medium releases heat and liquefies, and the liquefied cooling working medium flows back into the heat exchange tube 40 again to continue absorbing the heat inside the motor stator 30. And so on in a cycle.

[0043] Thus, through the cyclic flow and phase change of the cooling working medium in the heat exchange tube 40, continuous heat dissipation of the motor stator 30 can be achieved, effectively reducing the temperature of the motor stator 30, especially the temperature on the side adjacent to the motor rotor 20 in the radial direction, and further improving the working performance of the motor rotor 20 and even the flywheel energy storage device 100.

[0044] Moreover, affected by the temperature reduction of the part of the motor stator 30 close to the motor rotor 20, the temperature field gradient between the motor rotor 20 and the motor stator 30 can be increased. This can enhance the thermal radiation intensity between the motor rotor 20 and the motor stator 30, making it easier for the heat of the motor rotor 20 to be conducted to the motor stator 30, and then transferred to the external environment by the cooling working fluid in the heat exchange tube 40 inside the motor stator 30. Thus, the heat dissipation capacity of the motor rotor 20 can be improved, the temperature of the motor rotor 20 can be reduced, the remanence of the permanent magnet can be increased, and further the working performance of the motor rotor 20 and even the flywheel energy storage device 100 can be enhanced.

[0045] Therefore, through the arrangement of the heat exchange tube 40, not only the continuous heat dissipation of the motor stator 30 is realized, the temperature of the part of the motor stator 30 adjacent to the motor rotor 20 in the radial direction is effectively reduced, but also the thermal radiation intensity between the motor rotor 20 and the motor stator 30 can be enhanced, and the temperature of the motor rotor 20 can be reduced, thereby improving the working performance of the flywheel energy storage device 100.

[0046] Combined Figures 1-6 As shown, the first heat exchange tube 41 extends in the vertical direction, the second heat exchange tube 42 is at least partially bent in the vertical direction, and the two ends of the second heat exchange tube 42 close to the outside are connected to the first heat exchange tube 41.

[0047] Specifically, by arranging the first heat exchange tube 41 to extend in the vertical direction, the second heat exchange tube 42 is at least partially bent in the vertical direction, and the two ends of the second heat exchange tube 42 are connected to the first heat exchange tube 41, so that the overall shape of the heat exchange tube 40 is in a "return" shape, enabling the cooling working fluid to naturally circulate in a closed loop while undergoing a phase change.

[0048] Specifically, due to gravity, the liquid cooling working fluid accumulates in the lower part of the heat exchange tube 40, that is, at least in the lower part of the first heat exchange tube 41 and the lower part of the second heat exchange tube 42. After the flywheel energy storage device 100 starts to work, the motor stator 30 and the motor rotor 20 generate heat. The cooling working fluid located in the second heat exchange tube 42 can absorb heat and vaporize. The gaseous cooling working fluid, due to its lower density, can naturally transfer along the second heat exchange tube 42 to the first heat exchange tube 41.

[0049] Moreover, since the first heat exchange tube 41 is located outside the motor housing 10 and its temperature is relatively low, the gaseous cooling working fluid can exchange heat with the external environment at the first heat exchange tube 41. The gaseous cooling working fluid releases heat and liquefies, forming liquid cooling working fluid again, and then falls to the bottom of the first heat exchange tube 41 under the action of gravity. Then, with the accumulation of the liquid cooling working fluid, it enters the second heat exchange tube 42 again. This cycle continues.

[0050] Thus, by optimizing the structure of the heat exchange tube 40 and utilizing the phase change of the cooling working fluid, a self-circulation of the cooling working fluid in the heat exchange tube 40 can be achieved without external power. Compared with other cooling methods, this can avoid the use of additional power drive, thereby simplifying the structure of the flywheel energy storage device 100 and reducing the cost of the flywheel energy storage device 100 on the premise of ensuring the reduction of the temperatures of the motor stator 30 and the motor rotor 20.

[0051] Combined with Figure 4 As shown, the motor stator 30 may include: a stator winding 31 and a stator lamination 32. The stator winding 31 is wound around the stator lamination 32. The stator lamination 32 is fixedly connected to the motor housing 10 and is provided with an avoidance channel 321. At least a part of the second heat exchange tube 42 is disposed in the avoidance channel 321.

[0052] Specifically, winding the stator winding 31 around the stator lamination 32 and fixedly connecting the stator lamination 32 to the motor housing 10 can achieve the fixed connection between the motor stator 30 and the motor housing 10. The stator lamination 32 can provide support for the stator winding 31 to ensure the stable arrangement of the stator winding 31. It can be understood that the heat of both the stator winding 31 and the motor rotor 20 can be transferred to the stator lamination 32.

[0053] By arranging the avoidance channel 321 in the stator lamination 32 and disposing at least a part of the second heat exchange tube 42 in the avoidance channel 321, the arrangement position of the second heat exchange tube 42 can be optimized.

[0054] On the one hand, it can ensure the stable arrangement of the second heat exchange tube 42, not only avoiding interference between the second heat exchange tube 42 and the stator winding 31, but also playing a protective role for the second heat exchange tube 42, thereby ensuring the structural reliability of the second heat exchange tube 42.

[0055] On the other hand, it can enable the second heat exchange tube 42 to be in stable contact with the stator lamination 32, thereby ensuring the absorption of the heat transferred to the stator lamination 32 by the second heat exchange tube 42, further improving the heat dissipation efficiency of the motor stator 30 and the motor rotor 20, effectively reducing the temperatures of the motor stator 30 and the motor rotor 20, and improving the working performance of the flywheel energy storage device 100.

[0056] Combined with Figure 4 、 Figure 6 and Figure 7As shown, the second heat exchange tube 42 may include: a first heat exchange portion 421, a second heat exchange portion 422, and a third heat exchange portion 423 that are connected in sequence. The first heat exchange portion 421 and the third heat exchange portion 423 are arranged to extend radially and are spaced apart in the vertical direction, and the second heat exchange portion 422 is arranged to extend in the vertical direction. Correspondingly, the avoidance channel 321 may include: a first avoidance portion 3211, a second avoidance portion 3212, and a third avoidance portion 3213 that are connected in sequence. The first avoidance portion 3211 and the third avoidance portion 3213 are arranged to extend radially and are spaced apart in the vertical direction, and the second avoidance portion 3212 is arranged to extend in the vertical direction and is adjacent to the motor rotor 20 in the radial direction.

[0057] In this way, the structure of the second heat exchange tube 42 can be adapted to the structure of the avoidance channel 321. Only by arranging the first heat exchange portion 421 in the first avoidance portion 3211, the second heat exchange portion 422 in the second avoidance portion 3212, and the third heat exchange portion 423 in the third avoidance portion 3213 can the stable setting of the second heat exchange tube 42 in the stator lamination 32 be achieved.

[0058] Moreover, it can be understood that in this way, the second heat exchange tube 42 can be integrally U-shaped with an opening facing outward. The extending direction of the second heat exchange portion 422 is parallel to the axial direction of the motor rotor 20, and the second heat exchange portion 422 is adjacent to the motor rotor 20 in the radial direction.

[0059] Thereby, the structure and the setting position of the second heat exchange tube 42 can be further optimized, so that the first heat exchange portion 421 and the third heat exchange portion 423 dissipate heat from the nearby stator lamination 32 in the radial direction, and the second heat exchange portion 422 dissipates heat from the stator lamination 32 on the side close to the motor rotor 20 in the radial direction, ensuring the heat dissipation efficiency, and further effectively reducing the temperature of the motor stator 30, especially the temperature of the motor stator 30 on the side adjacent to the motor rotor 20 in the radial direction.

[0060] Combined Figure 4 and Figure 8 As shown, the motor housing 10 is provided with a first avoidance hole 11 and a second avoidance hole 12. The first avoidance hole 11 avoids the first heat exchange portion 421, and the second avoidance hole 12 avoids the third heat exchange portion 423.

[0061] Specifically, by providing a first avoidance hole 11 and a second avoidance hole 12 on the motor housing 10, the first avoidance hole 11 and the second avoidance hole 12 are spaced apart in the up and down direction. In this way, during assembly, the first heat exchange portion 421 can pass through the first avoidance hole 11, and the third heat exchange portion 423 can pass through the second avoidance hole 12. That is, when the first heat exchange portion 421 and the third heat exchange portion 423 pass through the motor housing 10 to reach the inside of the motor stator 30, the first avoidance hole 11 and the second avoidance hole 12 can respectively avoid them, thereby facilitating the installation of the heat exchange tube 40 and ensuring the normal operation of the flywheel energy storage device 100.

[0062] Combined Figure 4 with Figure 8 As shown, a first fin 13 is provided on the circumferential outer side of the motor housing 10. The first fin 13 extends in the up and down direction. The first fin 13 is multiple and spaced apart circumferentially. An avoidance groove 14 is formed between two adjacent first fins 13. The first avoidance hole 11 and the second avoidance hole 12 are respectively communicated with the avoidance groove 14.

[0063] Specifically, a first fin 13 is provided on the circumferential outer side of the motor housing 10. The first fin 13 extends in the up and down direction. The first fin 13 is multiple and spaced apart circumferentially. In this way, the multiple first fins 13 can increase the heat dissipation area of the motor housing 10, and an avoidance groove 14 is formed between two adjacent first fins 13. The avoidance groove 14 can allow the flow of external air, thereby enhancing the heat transfer efficiency of the motor housing 10, enabling the heat on the side of the motor stator 30 adjacent to the motor housing 10 to be dissipated to the external environment through the motor housing 10, ensuring the heat dissipation efficiency of the part of the motor stator 30 adjacent to the motor housing 10, and reducing the temperature of the motor stator 30.

[0064] Furthermore, by respectively communicating the first avoidance hole 11 and the second avoidance hole 12 with the avoidance groove 14, the setting positions of the first avoidance hole 11 and the second avoidance hole 12 can be optimized, and at least part of the first heat exchange portion 421 and the third heat exchange portion 423 can be located in the avoidance groove 14, thereby avoiding the influence of the setting of the heat exchange tube 40 on the heat dissipation of the motor housing 10.

[0065] Combined Figure 4 with Figure 6 As shown, a liquefaction portion 411 is provided at the upper end of the first heat exchange tube 41. A second fin 412 is provided on the outer side of the liquefaction portion 411. The second heat exchange tube 42 is connected below the liquefaction portion 411.

[0066] Specifically, by providing a liquefaction part 411 at the upper end of the first heat exchange tube 41 and providing a second fin 412 on its outer side, through the design of the second fin 412, not only the heat transfer area can be increased, but also the convective heat transfer and thermal radiation can be enhanced, thereby ensuring the heat transfer capacity of the liquefaction part 411.

[0067] By connecting the second heat exchange tube 42 below the liquefaction part 411, the gaseous cooling working fluid flowing out of the second heat exchange tube 42 can further float into the first heat exchange tube 41 and then into the liquefaction part 411, where it exchanges heat with the external air and liquefies, thereby ensuring the liquefaction efficiency, ensuring the self-circulation of the cooling working fluid in the closed loop, and ensuring the heat dissipation and temperature reduction of the motor stator 30.

[0068] Furthermore, as shown in Figure 6 a plurality of second fins 412 are provided. The plurality of second fins 412 are spaced apart in the axial direction and / or circumferential direction of the liquefaction part 411. In this way, the heat dissipation area can be further increased by the plurality of second fins 412, and the heat transfer can be strengthened, thereby further improving the heat transfer capacity of the liquefaction part 411, improving the liquefaction efficiency of the gaseous cooling working fluid floating into the liquefaction part 411, and further ensuring the self-circulation of the cooling working fluid in the closed loop and ensuring the heat dissipation and temperature reduction of the motor stator 30.

[0069] As shown in Figure 1 and Figure 5 a plurality of heat exchange tubes 40 are provided. The plurality of heat exchange tubes 40 are spaced apart in the circumferential direction of the motor stator 30.

[0070] Specifically, a plurality of heat exchange tubes 40 can be provided. Correspondingly, a plurality of first avoidance holes 11 and second avoidance holes 12 on the motor housing 10 are also provided and spaced apart in the circumferential direction, and a plurality of avoidance channels 321 on the stator lamination 32 are also provided and spaced apart in the circumferential direction, so that the plurality of heat exchange tubes 40 can be spaced apart in the circumferential direction.

[0071] In this way, each heat exchange tube 40 can cool and dissipate heat from the nearby part of the motor stator 30 through the phase change of the internal cooling working fluid, and the plurality of heat exchange tubes 40 spaced apart in the circumferential direction can achieve uniform heat dissipation of the entire motor stator 30 in the circumferential direction, ensuring the heat dissipation performance and improving the heat dissipation uniformity.

[0072] Furthermore, after ensuring the uniform heat dissipation of the entire motor stator 30 in the circumferential direction, the temperature gradient between the motor stator 30 and the motor rotor 20 can be made more uniform in the circumferential direction, thereby achieving uniform heat dissipation of the entire motor rotor 20 in the circumferential direction, ensuring the heat dissipation performance and improving the heat dissipation uniformity.

[0073] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0074] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0075] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present utility model, and the scope of the present utility model is defined by the claims and their equivalents.

Claims

1. A flywheel energy storage device, characterized in that, Comprising: Motor housing; Motor stator, the motor stator is arranged inside the motor housing and fixedly connected to the motor housing, and the motor stator is provided with an accommodation space; Motor rotor, the motor rotor is rotatably arranged in the accommodation space; Heat exchange tube, a closed loop is formed inside the heat exchange tube and a cooling working medium flows through it. The heat exchange tube includes a first heat exchange tube and a second heat exchange tube that are connected to each other. The first heat exchange tube is located outside the motor housing, the second heat exchange tube penetrates the motor housing and is located inside the motor stator, and at least part of the second heat exchange tube is arranged adjacent to the motor rotor in the radial direction of the motor stator.

2. The flywheel energy storage device according to claim 1, wherein, The first heat exchange tube extends in the up-down direction, the second heat exchange tube is at least partially bent in the up-down direction, and both ends of the second heat exchange tube close to the outside are connected to the first heat exchange tube.

3. The flywheel energy storage device according to claim 2, characterized in that, The motor stator includes: a stator winding and a stator lamination. The stator winding is wound around the stator lamination. The stator lamination is fixedly connected to the motor housing and is provided with an avoidance channel, and at least part of the second heat exchange tube is arranged in the avoidance channel.

4. The flywheel energy storage device according to claim 3, characterized in that, The second heat exchange tube includes: a first heat exchange part, a second heat exchange part and a third heat exchange part that are connected in sequence. The first heat exchange part and the third heat exchange part extend in the radial direction and are spaced in the up-down direction, and the second heat exchange part extends in the up-down direction; The avoidance channel includes: a first avoidance part, a second avoidance part and a third avoidance part that are connected in sequence. The first avoidance part and the third avoidance part extend in the radial direction and are spaced in the up-down direction, and the second avoidance part extends in the up-down direction and is adjacent to the motor rotor in the radial direction; The first heat exchange part is arranged in the first avoidance part, the second heat exchange part is arranged in the second avoidance part, and the third heat exchange part is arranged in the third avoidance part.

5. The flywheel energy storage device according to claim 4, characterized in that, The motor housing is provided with a first avoidance hole and a second avoidance hole. The first avoidance hole avoids the first heat exchange part, and the second avoidance hole avoids the third heat exchange part.

6. The flywheel energy storage device according to claim 5, wherein, A first fin is arranged on the circumferential outer side of the motor housing. The first fin extends in the up-down direction. The first fins are multiple and are spaced in the circumferential direction. An avoidance groove is formed between two adjacent first fins, and the first avoidance hole and the second avoidance hole are respectively connected to the avoidance groove.

7. The flywheel energy storage device according to claim 2, wherein, A liquefaction part is arranged at the upper end of the first heat exchange tube. A second fin is arranged on the outer side of the liquefaction part. The second heat exchange tube is connected below the liquefaction part.

8. The flywheel energy storage device according to claim 7, wherein, The second fins are multiple, and the multiple second fins are spaced in the axial direction and / or circumferential direction of the liquefaction part.

9. The flywheel energy storage device according to claim 1, characterized in that, The heat exchange tubes are multiple, and the multiple heat exchange tubes are spaced in the circumferential direction of the motor stator.

10. The flywheel energy storage device according to claim 1, characterized in that, Also comprising: An upper end cover assembly, a lower end cover assembly and a flywheel rotor. The upper end cover assembly is arranged at the upper end of the motor housing and fixedly connected to the motor housing. The lower end cover assembly is arranged at the lower end of the motor housing and fixedly connected to the motor housing. The flywheel rotor is arranged inside the motor housing and connected below the motor rotor. Magnetic suspension bearings are respectively arranged inside the upper end cover assembly and the lower end cover assembly, so that the flywheel rotor and the motor rotor are selectively magnetically suspended in the up and down directions.

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